title: The differential effects of reward on space- and object-based attentional allocation.
abstract: Estimating reward contingencies and allocating attentional resources to a subset of relevant information are the most important contributors to increasing adaptability of an organism. Although recent evidence suggests that reward- and attention-based guidance recruits overlapping cortical regions and has similar effects on sensory responses, the exact nature of the relationship between the two remains elusive. Here, using event-related fMRI on human participants, we contrasted the effects of reward on space- and object-based selection in the same experimental setting. Reward was either distributed randomly or biased a particular object. Behavioral and neuroimaging results show that space- and object-based attention is influenced by reward differentially. Space-based attentional allocation is mandatory, integrating reward information over time, whereas object-based attentional allocation is a default setting that is completely replaced by the reward signal. Nonadditivity of the effects of reward and object-based attention was observed consistently at multiple levels of analysis in early visual areas as well as in control regions. These results provide strong evidence that space- and object-based allocation are two independent attentional mechanisms, and suggest that reward serves to constrain attentional selection.
authors.affiliation: Department of Psychology, George Washington University, Washington, DC 20052, USA. jeongmi@gwmail.gwu.edu
authors.forename: Jeongmi
authors.initials: J
authors.lastname: Lee
authors.forename: Sarah
authors.initials: S
authors.lastname: Shomstein
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001519:Behavior / Q000502:physiology; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D003463:Cues; D003627:Data Interpretation, Statistical; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D012055:Reinforcement Schedule; D012201:Reward; D017603:Signal Detection, Psychological / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen